Optical imaging systems are commonly incorporated in personal electronic devices such as mobile phones, tablet computers, and the like. The optical imaging systems include an image sensor responsive to incident light and lens elements to direct and focus light onto the image sensor so as to form an image of an object external to the device in which the optical imaging system is incorporated. Such optical imaging systems can include multiple lens elements, and a lens barrel can be provided to hold the lens elements in alignment with each other along an optical axis. In some designs, light reflecting off a surface of the lens barrel can pass through the lenses and impinge on the image sensor. This can produce flare and other artifacts that can adversely affect image quality.